Ferrule



FIG. 1 is an environment perspective view of the ferrule with the broken line showing of a seismic cable being for illustrative purposes only and forming no part of the claimed design;

FIG. 2 is an end view of the ferrule;

FIG. 3 is a side view of the ferrule; and,

FIG. 4 is a top view of the ferrule. 

The ornamental design for a ferrule, as shown and described. 